Five years after the worst blackout in U.S. history, the country has strengthened the reliability of the electricity grid. But new challenges in demand, investment and energy resources leave the system vulnerable to another large-scale failure, experts and government officials say.
"The events that led to the 2003 blackout are now much less likely to occur," said Richard Sergel, president and CEO of the North American Electric Reliability Corporation, the nongovernmental agency overseeing...Full Story